From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20090225150831.217373674@de.ibm.com> References: <20090225150622.529143164@de.ibm.com> Date: Wed, 25 Feb 2009 16:06:37 +0100 From: Martin Schwidefsky Subject: [patch/s390 15/46] lockdep: trace hardirq off in smp_send_stop Content-Disposition: inline; filename=114-lockdep-send-stop.diff Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Cc: Heiko Carstens , Christian Borntraeger , Martin Schwidefsky List-ID: From: Christian Borntraeger With lockdep we got the following trace after a panic: Badness at /home/autobuild/BUILD/linux-2.6.28-20090204/kernel/lockdep.c:2878 [...] Call Trace: [<0000000000176334>] lock_acquire+0x54/0xbc [<000000000050b4fe>] __atomic_notifier_call_chain+0x6e/0xdc [<000000000050b59c>] atomic_notifier_call_chain+0x30/0x44 [<0000000000504274>] panic+0xd0/0x1e8 [...] INFO: lockdep is turned off. Last Breaking-Event-Address: [<0000000000170e62>] check_flags+0xae/0x15c possible reason: unannotated irqs-off. lockdep is right. We missed a trace_hardirq_off in our smp_send_stop function and smp_send_stop is called before the panic call chain. Reported-by: Mijo Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/smp.c | 2 ++ 1 file changed, 2 insertions(+) Index: quilt-2.6/arch/s390/kernel/smp.c =================================================================== --- quilt-2.6.orig/arch/s390/kernel/smp.c +++ quilt-2.6/arch/s390/kernel/smp.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -75,6 +76,7 @@ void smp_send_stop(void) /* Disable all interrupts/machine checks */ __load_psw_mask(psw_kernel_bits & ~PSW_MASK_MCHECK); + trace_hardirqs_off(); /* stop all processors */ for_each_online_cpu(cpu) { -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.